1. Field of the Invention
The present invention relates to a plasma display panel, and more particularly to an improvement in composition of mixed green-color fluorescent materials for a plasma display panel.
2. Description of the Related Art
In color plasma display panels, it has been known to a person skilled in the art that plural kinds of green-color fluorescent materials are mixed to adjust a chromaticity of green color.
Japanese laid-open patent publication No. 2001-135239 discloses that Zn2SiO4:Mn fluorescent material and a terbium (Tb) rare earth oxide fluorescent material are mixed to adjust the chromaticity of green color. FIG. 1 is a chromaticity coordinate of Zn2SiO4:Mn fluorescent material, YBO3:Tb fluorescent material, and LaPO4:Tb fluorescent material. This conventional technique uses the Zn2SiO4:Mn fluorescent material which is, however, disadvantageous because the Zn2SiO4:Mn fluorescent material may increase the driving voltage for the plasma display panel. The Zn2SiO4:Mn fluorescent material is further disadvantageous in fast deterioration in luminance. For those reasons, it is preferable to avoid the use of Zn2SiO4:Mn fluorescent material as the green color fluorescent material.
In the above circumstances, the development of a novel composition of a mixed green color fluorescent material for adjusting a green color chromaticity in connection with a plasma display panel free from the above problems is desirable.
Accordingly, it is an object of the present invention to provide a novel composition of a mixed green color fluorescent material for adjusting a green color chromaticity in connection with a plasma display panel free from the above problems.
It is a further object of the present invention to provide a novel composition of a mixed green color fluorescent material for adjusting a green color chromaticity in connection with a plasma display panel, wherein the mixed green color fluorescent material is free of Zn2SiO4:Mn fluorescent material.
It is a still further object of the present invention to provide a novel composition of a mixed green color fluorescent material for adjusting a green color chromaticity in connection with a plasma display panel, wherein the mixed green color fluorescent material does not cause any substantive increase of the driving voltage for the plasma display panel.
It is yet a further object of the present invention to provide a novel composition of a mixed green color fluorescent material for adjusting a green color chromaticity in connection with a plasma display panel, wherein the mixed green color fluorescent material does not cause any deterioration of luminance of the plasma display panel.
The present invention provides a mixed green color fluorescent material for an electric device such as a plasma display panel. The mixed green color fluorescent material includes: at least a first fluorescent material selected from a Group A defined in a range (0.10xe2x89xa6xxe2x89xa60.18, 0.70 xe2x89xa6yxe2x89xa60.80) on a chromaticity coordinate; and at least a second fluorescent material selected from a Group B defined in a range (0.25xe2x89xa6xxe2x89xa60.35, 0.55 xe2x89xa6yxe2x89xa60.65) on the chromaticity coordinate.
The above and other objects, features and advantages of the present invention will be apparent from the following descriptions.